Current methods of masking logos and other various shapes and designs for painting airplane exteriors involve hand measurements, sometimes assisted by mylar alignment tools, which measurements are used as guides for accurate placement of paper stencils, or "pre-masks," which have been pre-cut with the outline of the design that is to be painted. These pre-masks are then affixed by their adhesive backing to the skin of the airplane over the base-coat of paint (color .pi.1). Alternatively, the design may be formed by hand application of masking tape and butcher paper around the perimeter of the design. Again, this taping process may utilize hand measurements or may be aided by the use of mylar positioning and alignment tools. The second color (color #2) is then painted over the stencil which can then be removed. This process is repeated one or more times for multicolored designs.
There are a number of concerns with this current masking method. First, due to the bulkiness and size of many of the stencils and pre-masks, and the need for accurate placement, decorative masking is a difficult and time consuming job, sometimes requiring substantial rework. In the masking of airplanes, the problem is compounded in the paint hangers, at the end of the airplane's production cycle where flow time is most expensive. Second, the masking tape used to apply the pre-masks and stencils requires that the underlying base coat undergo a comparatively long cure time in order to avoid damage to the base coat when the tape is removed. The tape can also leave an adhesive residue that must be cleaned later. Third, full size templates and pre-masks must be created, maintained, and stored for each individual design. For airplane manufacturers, each airplane customer usually has a distinctive exterior decorative design, which is frequently updated. This requires a very large inventory of paper templates and pre-masks and creates a substantial logistics problem. Fourth, the current method does not lend itself to full implementation of all digital product design. Although templates and pre-masks can be (and currently are) cut using digital databases, any design iterations or other changes require creating and painting a whole new template to allow visualization of the new designs. The present invention is directed to a computerized laser masking method and apparatus that addresses these concerns.